1. Field of the Invention
The present invention relates to a signal processing method. More particularly, though not exclusively, a signal processing method for a digital camera and/or a video camera, using an image sensor.
2. Description of the Related Art
In a conventional image capture apparatus, light amount control is performed based on data on an amount of reflected light from a subject within an image frame at the time of flash photography.
Hence, in a case where there exists a subject having a high or low reflectance within an image frame, the amount of reflected light can adversely affect the light amount control.
For example, in a case where a subject puts on black clothes, if the conventional system is employed, since light amount control is performed based on data on an amount of reflected light from the subject within an image frame, the face of the subject is illuminated with more than an adequate amount of flash light.
As a result, the face of the subject is photographed in an overexposed state.
Hence, Japanese Patent Application Laid-Open No. 2003-107555 discuses a technique of detecting the face of a subject from a captured image before AF (Auto Focusing) and performing exposure control with the detected face area of the subject given weighting.
With the technique as described above, photography can be made in such a manner as to focus on the face of the subject, thereby allowing the face area to have a most suitable luminance.
However, for example, under the circumstance where luminance is not sufficient (in a case where a person is photographed with a night view for a background), it is difficult to accurately detect the face of the person from the captured image.
Additional conventional methods attempt to detect the face of a person, for example one method regards a flesh colored area having more than a predetermined size as a face area, while another method detects a contour of the face and a shape of the eyes from luminance information and regards them as a face area. However, typically detection accuracy is deteriorated in darkness in conventional methods.